Possibly best to go for a clean reinstall:
-
Download the latest version of avast Pro 6.0.1125 http://files.avast.com/iavs5x/setup_av_pro.exe and save it to your HDD, somewhere you can find it again (if you didn’t save your last download). Use that when you reinstall.
-
Download the avast! Uninstall Utility, aswClear.exe find it here and save it to your HDD (it has uninstall tools for both 5.x and 6.0.x).
-
- Now uninstall avast! (using add remove programs, if you can’t do that start from the next step), reboot.- 2. run the avast! Uninstall Utility from safe mode, first for 5.x if previously installed and then for 6.0, once complete reboot into normal mode.- 3. install the latest version, reboot.